80 gs750 won't top out

[mrbill5491]

I have the same bike and almost the same set up as you. Though when I added my pipe and K&N air filter all I did was step up the main jets. I also run ACCEL coils. Far as I know this bike won't top out in 5th gear, at least I never got mine too. My plugs run a med tan so I know my jets are just right for my altitude here. I'm at 4,000ft. Matter of fact my main jets are Mikuni 115s. Where are you located p_trice?
The big draw back on this bike are the cams. Just not enough cam to let it breath at the high end in 5th. I was once clocked at 114 in 4th

I have a 1980 gs750e. It has a 4 into 1 exhaust. It has the stock airbox and filter. it has a dynojet stage 1 kit with DJ116 main jets and the needles are at the 3rd groove from the top. It runs great, sounds great, and accelerates great. It won't quite top out though. In 5th gear the highest rpm i have hit so far is 7,500. It just seems like it should have a bit more top speed too it. Am i maybe running too lean or something near the top? My plugs r a nice brownish tan color near the bottom, but the electrode is whitish grey. Also, it seems like it pulls a bit harder near the top with the airbox lid off. Any thoughts?

[p_trice]

I am located in Illinois. at sea level. I have some 117.5 main jets on the way. they should do the trick for me. I plan on adding a k&n air filter too.

[platinum2]

I am located in Illinois. at sea level. I have some 117.5 main jets on the way. they should do the trick for me. I plan on adding a k&n air filter too.

where in ill?
its too lean, maybe drill those out with a baby bit, if your getting bigger jets, my bike 750ed came with 117.5,and the 700 comes with 122.5 mains
so with your loss of back pressure youll need bigger jets,always better richer than leaner
it will save 25 dollars!, your air box lid ,and k&n filter will change things as well

[p_trice]

thanks for the advice. I'm located in central Illinois, like right in the middle of the state. My new main jets will be here today. I'm ready to tear up some pavement.

[mrbill5491]

Think I would leave the air box lid on especially when you get the K&N air filter. I've tried running my bike without the air box lid once and it just didn't work good.

[p_trice]

my jets will be here any minute, the bike will be back together and running within the hour. I will post back after i take it on a test run. and thanks for the advice everyone.